Judge Backs PacifiCorp in Wyoming Rate Fight, Opening Door to Bigger Hike

A federal judge just handed PacifiCorp—and its Rocky Mountain Power unit—a win in their brawl with Wyoming regulators, a decision that could mean higher electric bills for customers down the line, Casper Star-Tribune reports.

US District Judge Kelly H. Rankin ruled that the Wyoming Public Service Commission (PSC) wrongly knocked down the company’s calculations in its 2023 rate case. At the center: a nerdy (but expensive) debate over how to model costs tied to federal grid rules.

Here’s the gist:

• The fight: PacifiCorp operates a multi-state power system and, under Federal Energy Regulatory Commission (FERC) rules, must keep some generating capacity in reserve to keep the grid reliable and open to third-party transmission. That costs money. To forecast the “just and reasonable” slice Wyoming customers should pay, the utility used the Aurora modeling tool.
• The PSC’s move: Wyoming regulators didn’t trust Aurora, chopped the modeled costs, and trimmed what PacifiCorp could collect in its 2023 case.
• The ruling: Rankin said the facts weren’t in dispute and granted summary judgment for PacifiCorp, effectively saying the PSC’s haircut unfairly reduced the recovery the utility is legally entitled to. He also flagged that these “trapped cost” fights are likely to keep coming back.

What it could mean for customers: unclear. An appeal is on the table, and any dollar impact still needs to be worked out. But the direction of travel isn’t hard to read.

Meanwhile, Wyoming customers have already felt it:

• A 5.5% general rate increase took effect in January 2024, plus two temporary fuel-cost surcharges.
• Earlier this year, the PSC approved a settlement with the Office of Consumer Advocate for another $85.5 million—about 10.2%—in higher rates.

The broader backdrop: state leaders have long suspected PacifiCorp of shifting too much of its regional grid costs onto Wyoming. The judge didn’t bless that narrative—or kill it. He focused on this specific modeling dispute and said the PSC went too far. The legal wrangling over who pays what for a shared, multi-state grid? That’s not going away.